Standardized Acceptance Thresholds for Starch Degradation and Peroxide Demand in Aged Cotton
Staged titration of residual active oxygen and TEGEWA violet scale ratings above six prevent catalytic fiber tenderization in aged cotton prep.
Amino-Polyphosphonate Sequestrants
Metal Stabilization
Organic chelating agents prevent the interference of polyvalent metal ions during the pretreatment and dyeing of cellulose fibers. Compounds known as amino-polyphosphonate sequestrants contain both amine groups and multiple phosphonic acid functional groups that form stable complexes with calcium, magnesium, iron and copper. By isolating these ions, the chemistry prevents the formation of insoluble soap scums and protects against the catalytic decomposition of hydrogen peroxide.
Bleaching Protection
Peroxide bleaching liquors require stabilization to maintain a controlled oxidation rate. The presence of amino-polyphosphonate sequestrants inhibits the rapid breakdown of the oxidant, which helps maintain a steady bleaching rate and prevents localized damage to the cotton fiber.
Application Range
Effectiveness over a wide ph range makes certain chemical additives suitable for continuous scouring and bleaching operations. Most formulations of amino-polyphosphonate sequestrants offer good dispersing properties that assist in the removal of silicate scale from machine surfaces. Their high affinity for iron makes them particularly useful in mills where the water supply is contaminated by rust from old piping.
Unlike some traditional chelators, these molecules provide superior stability at high temperatures.
Solubility Constraint
High concentrations of cationic surfactants often interfere with the anionic binding sites of chelating molecules. In such environments, the performance of amino-polyphosphonate sequestrants drops notably.